Ann S. Persson ran her hand gently across a primitive sunburst design carved into rock thousands of years ago. She traced lines radiating from the center to the rock's edge.
"It's like touching history, our connection from the past to the present," said Persson, curator of the Havre de Grace Maritime Museum, which today opens an exhibit of ancient rock art, known as petroglyphs.
Charlie Hall, the state's terrestrial archaeologist, will introduce the collection of rocks that he called "powerful communications devices" that date back about 4,000 years.
"You are touching deep, deep history, the core of humanity," Hall said. "These drawings were a means of communication that still communicate to us today. They shout `Look at me!' and completely draw you in."
The carvings help tell the story of life along the Susquehanna River, when Native Americans fished, hunted and camped along its shores.
"The Susquehanna was then like I-95 is today," Persson said. "The river was a major thoroughfare, a way to get to and from different resources."
The petroglyphs, carved with whatever stone tools were available, provide insights into the culture of the era. They may have served as trail markers denoting good fishing grounds or dangerous waters, archaeologists said.
"Who knows what the images are trying to tell us?" Persson said. "Maybe they were recording the climate or telling a creation story."
Images of fish, the sun and the water, as well as some early doodling -- concentric circles and squiggly lines -- once attracted 20th century explorers to a rock island in the river near the Harford-Cecil county line.
"People knew the drawings were there," Persson said. "Boaters would stop at the island and explore."
Before construction of the Conowingo Dam inundated that island more than 80 years ago, area residents insisted on preserving what has become known as the Bald Friar rocks, named for the area where they were discovered.
"The rocks were saved and that's a testament to the citizens of the area," Hall said, adding that more than 30 petroglyphs are now protected state property that will be shared with the public.
After they were removed from the rock island, the petroglyphs were displayed at Druid Hill Park in Baltimore for many decades, but have since been restored and preserved at the Maryland Archaeological Conservation Laboratory in Calvert County. The lab's staff has studied, analyzed and catalogued the collection, which will be shared with museums throughout the state.
